Here are Jonn’s notes relating to his work on one of our new arrivals – a 1976 Chevrolet Corvette:
Inspect brake system. Carry out full manual bleed of system. Still,think air is trapped in system. Attempt to pressure bleed but unable to seal reservoir. Bleed full system from master cylinder through to each wheel in order. Light still comes on occasionally and pressure at proportion valve seems unequal across the two circuits when unions undone and pedal,pressure applied, making me think there is still air trapped in system.
Looking into why the brake warning light was flashing on. After checking and bleed the brakes we found the new switch in the pressure senor valve was faulty. Also a few things we found which will require attention in the future. A bump stop becoming delamination and the radiator cross member show signs of corrosion.
Clamp off 3 wheels and bleed 4th. Repeat process for all wheels. Pedal good but light still illuminates when pedal pressed. Clamp off both fronts and retry. Light still coming on. Clamp off rears and try to see which circuit has the lower pressure. But light still coming on. Check old switch from old valve. Switch works like a reverse lightbswitch, as 8n when plunger pressed in switch then has continuity to earth, illuminating light on dash. Reiver new switch from new valve and found switch already has continuity without pressing in plunger. Wobble plunger and switch loses continuity. Fit old switch into new valveand test. Hey presto, light no longer illuminates when pedal pressed. Top up fluid. Refit wheels and torque up to 108nm. Clean area and have quick final look over ( see attached advisories). Carry out road test, all ok. Brakes fine and light not illuminating. ADVISE, All wheels show signs of wear where wheel nuts contact. Handbrake has excessive travel. Drivers side rear bumper stop hanging off. Wire to drivers side rear routed poorly above rear shock absorber. Radiator mount/ ember corroded and holed. Plate beneath rear diff insecure and rattles.